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Journal of Agriculture, Victoria. [11 Feb., 1918. 



type shown in Plate 150. This harness is comparatively light, and the 

 steel tube forming the bow is held up by the hip straps, and the traces 

 being of leather, there is no rough surface to come into contact with the 

 trees. As the draught is adjustable from straight behind the horse, 

 when ploughing on or off, there is no liability of the bow chafing the 

 horse's legs. 



The almost continuous and necessary alteration in the physical for- 

 mation of the surface of our orchard soils by ploughing and general 

 cultivation is carried on partly for the suppression of weeds. One of 

 the primary objects of cultivation, however, is to aerate the soil by 



Plate 148. — One-horse Spring Tooth Cultivator. 



Plate 149. — The One-way Extension Disc Cultivator. 



dividing up its particles, and thus encouraging bacterial activity, a 

 change so desirable in heavy, sour soils. A reason of no less import- 

 ance is to maintain the surface mulch by means of which the soil moisture 

 is conserved so that it may be available for the trees during dry 

 weather. 



A third or cross ploughing is often given, where the surface soil is 

 of a nature that becomes hard and closely packed after rain or irrigation, 

 to maintain a state of intense cultivation; but, when practised, this work 

 should be carried out at a time when surface drainage would not be 

 interfered with. In the vast majority of orchards, however, the cross- 

 ploughing may practically be obviated by occasionally cross or diagonally 



